1. Field of the Invention
The present invention relates to a welding transformer to be used in a welding gun for robot.
2. Prior Art
A conventional welding transformer to be used in a welding gun for robot is disposed within a cradle as illustrated in FIG. 3.
The welding gun for robot having welding gun arms 11 and 12 is attached to a robot wrist by way of a cradle 13. The cradle 13 comprises a hollow frame having a pivotal mounting portion at one end thereof on which the welding gun arms 11 and 12 are pivotally mounted and an attaching portion 14 at the other end thereof to be fixed to the robot wrist. A welding transformer 15 has holding frames 16 and 16 fixed thereto at the front and rear portions and both sides thereof for holding a core of the welding transformer 15, and the holding frames 16 and 16 are fixed to the cradle 13 whereby the welding transformer 15 is disposed within and fixed to the cradle 13, which is typically disclosed in Japanese patent Publication No. 62-11950.
Inasmuch as the welding gun is movable freely by the robot, the welding transformer will be violently movable accompanied by the movement of the welding gun. Hence, the welding transformer has to be as light as possible. Furthermore, the transformer has to be replaced with another transformer depending on the kind of work.
However, since the conventional welding transformer has the holding frames 16 which are fixed to the cradle 13, the welding transformer 15 is heavy. Still furthermore, there was needed such additional assembling and disassembling operations that the welding transformer is attached to or removed from the cradle in addition to removing the cradle 13 from the robot wrist.